Cardiovascular & Excretory
Identify the four chambers of the heart.
right atrium, right ventricle, left atrium, and left ventricle
List the six main organs of the digestive system and identify one function of each.
Identify five major bones in your skeleton and describe where each one is located in your body.
List four ways your body defends itself against germs and pathogens.
Describe how your digestive and circulatory systems work together when you eat a meal.
When you eat, your digestive system breaks down food into nutrients. Your small intestine absorbs these nutrients into the bloodstream. Your circulatory system then transports these nutrients throughout your body to cells that need them for energy and growth. The two systems must work together so your body can use the food you eat.
When you run a race and your heart beats faster, explain why this happens using what you know about the cardiovascular system.
When you run, your muscles need more oxygen and nutrients. Your heart beats faster to pump more blood to deliver oxygen and glucose to your hardworking muscles. This is your body's way of meeting increased energy demands during exercise.
When you eat a sandwich at lunch, explain the journey that food takes through your digestive system.
Your teeth chew the sandwich in your mouth, breaking it into smaller pieces. Saliva begins to break down the bread. You swallow, and it travels down your esophagus to your stomach, where acids break it down further. It then moves to your small intestine, where nutrients are absorbed into your blood. Any remaining material goes to the large intestine and eventually becomes waste.
When you bend your arm to pick up a book, explain which bones and muscles are involved in this movement.
The humerus (upper arm bone) and radius/ulna (forearm bones) are the bones involved. The biceps muscle contracts (shortens) to bend your arm, while the triceps muscle relaxes. The bones act as levers, and the muscles provide the force to move them.
When you get a cut on your finger, explain how your immune system protects you from infection.
When your skin is cut, germs can enter your body. Your white blood cells rush to the area to fight the invading pathogens. Your body also produces antibodies that specifically target those germs. Inflammation (redness and swelling) is your body's way of fighting the infection. Eventually, your immune system defeats the germs and the cut heals.
Explain how your respiratory and circulatory systems work together to deliver oxygen to your muscles during exercise.
When you exercise, you breathe faster. Your respiratory system takes in more oxygen through your lungs. Your circulatory system picks up this oxygen-rich blood from your lungs and pumps it to your hard-working muscles. Your muscles use the oxygen to produce energy. Without both systems working together, your muscles wouldn't get the oxygen they need.
Compare the jobs of arteries and veins by describing how they are different.
Arteries carry oxygen-rich blood away from the heart to all parts of the body. Veins carry oxygen-poor blood back to the heart. Arteries have thick, muscular walls, while veins have thinner walls. Both are essential for circulation.
Compare what happens to oxygen in your respiratory system versus what happens to food in your digestive system.
In the respiratory system, oxygen enters through your nose or mouth, travels down the trachea to your lungs, and is absorbed into the blood. In the digestive system, food enters your mouth, is broken down chemically and physically, travels through several organs, and nutrients are absorbed into the blood. Both systems break down materials and get them into your bloodstream.
Compare the three types of joints in your body by describing how each one moves.
Compare the structures of the kidneys and the bladder by describing what each organ does.
The kidneys are bean-shaped organs that filter waste and excess water from the blood to create urine. The bladder is a muscular sac that stores urine until you are ready to go to the bathroom. The kidneys do the filtering work, while the bladder holds the waste temporarily.
Compare how your skeletal system, muscular system, and nervous system work together to help you catch a ball.
Your eyes see the ball coming (nervous system). Your nervous system sends signals to your muscles telling them to move. Your muscles contract and pull on your bones (skeletal system), moving your arms and hands into position. Your skeleton provides the structure that allows movement. All three systems must coordinate perfectly for you to successfully catch the ball.
Classify the following as either a function of the cardiovascular system or the excretory system: delivering oxygen, removing urea, transporting nutrients, filtering blood.
Cardiovascular system: delivering oxygen, transporting nutrients. Excretory system: removing urea, filtering blood. (Note: The kidneys filter blood to remove waste, which is part of the excretory system.)
Classify the following as part of the respiratory system or digestive system: trachea, esophagus, lungs, stomach, diaphragm, small intestine.
Respiratory system: trachea, lungs, diaphragm. Digestive system: esophagus, stomach, small intestine.
Classify the following muscles as voluntary or involuntary: heart muscle, biceps, stomach muscle, quadriceps.
Voluntary: biceps, quadriceps (you control these). Involuntary: heart muscle, stomach muscle (they work automatically without you thinking about them).
Classify the following as functions of the immune system or urinary system: fighting bacteria, filtering blood, producing antibodies, removing urea, protecting against viruses.
Immune system: fighting bacteria, producing antibodies, protecting against viruses. Urinary system: filtering blood, removing urea.
Classify the following scenarios by which body systems are involved: digesting breakfast, running a race, fighting off a cold, filtering waste from blood.
Summarize how the cardiovascular and excretory systems work together to keep your body healthy by removing waste products.
The cardiovascular system transports blood throughout the body, carrying nutrients and oxygen. As cells use these materials, they produce waste like urea. The blood carries this waste to the kidneys (part of the excretory system), which filter it out. The cleaned blood is then returned to circulation, keeping your body healthy.
Summarize why you need both a healthy digestive system and a healthy respiratory system to have energy for playing sports.
Your digestive system breaks down food and absorbs nutrients like glucose into your blood. Your respiratory system takes in oxygen and puts it into your blood. Your cells need both glucose and oxygen to produce energy. Without either system working properly, your muscles wouldn't have the fuel and oxygen needed to perform during sports.
Summarize the relationship between your skeletal and muscular systems by explaining how they work together to help you walk.
Your skeleton provides the framework and bones that act as levers. Your muscles attach to these bones and contract to create movement. When you walk, your leg muscles contract and relax in a coordinated pattern, pulling on your leg bones to move them forward. Without both systems working together, walking would be impossible.
Summarize how the urinary system keeps your body healthy by explaining what happens to waste products in your blood.
As your cells use nutrients and oxygen, they produce waste products like urea. Your blood carries this waste to your kidneys, which filter it out along with excess water. This filtered waste becomes urine, which is stored in your bladder. When you urinate, these waste products leave your body. Without this system, toxic waste would build up in your blood and make you sick.
Summarize how all your body systems work together to keep you alive and healthy throughout the day.
Your digestive system breaks down food and absorbs nutrients. Your respiratory system takes in oxygen. Your circulatory system delivers oxygen and nutrients to every cell. Your muscular and skeletal systems allow you to move. Your immune system protects you from germs. Your urinary system removes waste. Your nervous system coordinates all these systems so they work together. Each system depends on the others, and together they keep your body functioning and healthy.